package com.shb.jutils.commons;

/**
 * 创建人：shenbing
 * 时间：2015-10-30
 * 来源：网络
 * 说明：对字符串编码和解码，类似于于JavaScript中的escape() 函数和unescape()函数
 * 不会对数字和字母编码，其他字符被替换成了十六进制的转义序列
 * Created by Administrator on 2015/10/30 0030.
 */
public class EscapeUnescapeUtil {
    private EscapeUnescapeUtil(){
    }

    public static String escape(String src){
        StringBuffer tmp = new StringBuffer();
        tmp.ensureCapacity(src.length() * 6);
        for(int i = 0; i < src.length(); i++){
            char j = src.charAt(i);
            if(Character.isDigit(j) || Character.isLowerCase(j)
                    || Character.isUpperCase(j)){
                tmp.append(j);
            }else if(j < 256){
                tmp.append("%");
                if(j < 16){
                    tmp.append("0");
                }
                tmp.append(Integer.toString(j, 16));
            } else {
                tmp.append("%u");
                tmp.append(Integer.toString(j, 16));
            }
        }
        return tmp.toString();
    }

    public static String unescape(String src) {
        StringBuffer tmp = new StringBuffer();
        tmp.ensureCapacity(src.length());
        int lastPos = 0, pos = 0;
        char ch;
        while (lastPos < src.length()) {
            pos = src.indexOf("%", lastPos);
            if (pos == lastPos) {
                if (src.charAt(pos + 1) == 'u') {
                    ch = (char) Integer.parseInt(src
                            .substring(pos + 2, pos + 6), 16);
                    tmp.append(ch);
                    lastPos = pos + 6;
                } else {
                    ch = (char) Integer.parseInt(src
                            .substring(pos + 1, pos + 3), 16);
                    tmp.append(ch);
                    lastPos = pos + 3;
                }
            } else {
                if (pos == -1) {
                    tmp.append(src.substring(lastPos));
                    lastPos = src.length();
                } else {
                    tmp.append(src.substring(lastPos, pos));
                    lastPos = pos;
                }
            }
        }
        return tmp.toString();
    }

    public static void main(String[] args){
        String tmp = "* @ - _ + . /";
        //String tmp=" ~!@#$%^&*()_+|\\=-,./?><;'][{}\"";
        System.out.println("testing escape : " + tmp);
        tmp = escape(tmp);
        System.out.println(tmp);
        System.out.println("testing unescape :" + tmp);
        System.out.println(unescape(tmp));
    }
}
